Preheat oven to 350°F. Line large baking sheet with parchment paper.
Whisk flour, baking powder, and salt in medium bowl to blend. Using electric mixer, beat sugar, eggs, oil, and almond extract or Amaretto liquor in large bowl until well blended. Add flour mixture and beat until smooth. Stir in pistachios, dried cranberries, and 3/4 cup chopped white chocolate by hand. Divide dough in half and form into two 12-inch-long strips on prepared baking sheet, spacing strips 3 inches apart. Using wet fingertips, shape each strip into 3-inch-wide log, pressing for even thickness. Logs may look slightly lumpy, but try to make the top as smooth as possible by pressing the cranberries and pistachios into the dough.
Bake logs until lightly browned, about 30 minutes. Cool logs on sheet for a minimum of 30 minutes. Reduce oven temperature to 325°F. Carefully transfer logs to cutting board and slice about 1/2-3/4-inch thick. Place them back on the same baking sheet with parchment paper (I used the same sheet) standing biscotti upright, spacing about 1/4 inch apart, in 3 rows. Bake until pale golden (biscotti may be soft but will firm as they cool), about 20 minutes. Allow to cool completely on baking sheet.
Line another large baking sheet with parchment paper. Place remaining chopped white chocolate in medium glass bowl. Microwave on a low temp for 30seconds at a time, until smooth. Dip one end or 1 side of each biscotti in chocolate; place on baking sheet. Chill until chocolate is set, about 30 minutes.